The invention relates generally to a method, apparatus, and system for packaging oxygen sensitive materials, and particularly to a method, apparatus, and system for triggering an oxygen scavenging film.
It is well known that limiting the exposure of oxygen sensitive articles to oxygen maintains and enhances the quality and shelf life of the article. For instance, by limiting the oxygen exposure of oxygen sensitive food articles in the packaging system, the quality of the food article is maintained and spoilage is reduced. In addition, such packaging also keeps the article in inventory longer thereby reducing restocking costs, and costs incurred from waste
Commonly used packaging systems include modified atmosphere packaging (MAP) and vacuum packaging in conjunction with oxygen barrier films. In these instances, reduced oxygen environments are employed at the time of packaging, while the oxygen barrier film reduces the amount of oxygen that physically enters the package during storage.
U.S. Pat. No. 5,211,875 to Speer et al. discloses methods and compositions for scavenging oxygen. The "oxygen scavenger" materials disclosed by Speer et al. are compositions which consume, deplete or reduce the amount of oxygen from a given environment.
Oxygen scavenging materials are useful in MAP and barrier packaging environments. However, oxygen scavenging materials typically require triggering or activation to bring on the oxygen scavenging properties, and delays referred to as an induction period are sometimes experienced before the onset of useful oxygen scavenging properties. Compositions exhibiting lengthy induction times must be held by an end user in inventory for a sufficient period of time before use. On the other hand, oxygen scavenging compositions having a shorter induction period must be used within a relatively short period of time so that the oxygen scavenging properties of the material are not prematurely exhausted.
The need remains for an effective method of triggering an oxygen scavenger film so as to trigger oxygen scavenging properties when desired, preferably a method having a short induction period so that the film can be triggered at or immediately prior to use during packaging of an oxygen sensitive article, and preferably one which is simple and readily incorporated into existing packaging procedures.
The need also remains for an apparatus for triggering an oxygen scavenging film so as to provide the film with a short or negligible induction period, preferably enhanced oxygen scavenging rate and longevity, preferably an apparatus which is readily incorporated in-line into existing packaging systems for triggering oxygen scavenging film at or immediately prior to packaging.